Understanding Snmp - Cisco Catalyst 3550 series Software Configuration Manual

Configuring SNMP
This chapter describes how to configure the Simple Network Management Protocol (SNMP) on your
Catalyst 3550 switch.
Note For complete syntax and usage information for the commands used in this chapter, refer to the switch
command reference for this release and to the Cisco IOS Configuration Fundamentals Command
Reference for Release 12.1.
This chapter consists of these sections:
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Understanding SNMP

SNMP is an application-layer protocol that provides a message format for communication between
managers and agents. The SNMP system consists of an SNMP manager, an SNMP agent, and a
management information base (MIB). The SNMP manager can be part of a network management system
(NMS) such as CiscoWorks. The agent and MIB reside on the switch. To configure SNMP on the switch,
you define the relationship between the manager and the agent.
The SNMP agent contains MIB variables whose values the SNMP manager can request or change. A
manager can get a value from an agent or store a value into the agent. The agent gathers data from the
MIB, the repository for information about device parameters and network data. The agent can also
respond to a manager's requests to get or set data.
An agent can send unsolicited traps to the manager. Traps are messages alerting the SNMP manager to
a condition on the network. Traps can mean improper user authentication, restarts, link status (up or
down), MAC address tracking, closing of a TCP connection, loss of connection to a neighbor, or other
significant events.
This section includes information about these topics:
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78-11194-09
Understanding SNMP, page 27-1
Configuring SNMP, page 27-5
Displaying SNMP Status, page 27-17
SNMP Versions, page 27-2
SNMP Manager Functions, page 27-3
SNMP Agent Functions, page 27-4
SNMP Community Strings, page 27-4
C H A P T E R
Catalyst 3550 Multilayer Switch Software Configuration Guide
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